diff --git a/antlr4-maven-plugin/src/main/java/org/antlr/mojo/antlr4/Antlr4Mojo.java b/antlr4-maven-plugin/src/main/java/org/antlr/mojo/antlr4/Antlr4Mojo.java
index 8786b3177..22e942ea6 100644
--- a/antlr4-maven-plugin/src/main/java/org/antlr/mojo/antlr4/Antlr4Mojo.java
+++ b/antlr4-maven-plugin/src/main/java/org/antlr/mojo/antlr4/Antlr4Mojo.java
@@ -268,9 +268,9 @@ public class Antlr4Mojo extends AbstractMojo {
             grammarFiles = getGrammarFiles(sourceDirectory);
             importGrammarFiles = getImportFiles(sourceDirectory);
             argumentSets = processGrammarFiles(args, grammarFiles, dependencies, sourceDirectory);
-        } catch (InclusionScanException ie) {
-            log.error(ie);
-            throw new MojoExecutionException("Fatal error occured while evaluating the names of the grammar files to analyze", ie);
+        } catch (Exception e) {
+            log.error(e);
+            throw new MojoExecutionException("Fatal error occured while evaluating the names of the grammar files to analyze", e);
         }
 
 		log.debug("Output directory base will be " + outputDirectory.getAbsolutePath());
@@ -385,7 +385,7 @@ public class Antlr4Mojo extends AbstractMojo {
         List<String> args,
         Set<File> grammarFiles,
         GrammarDependencies dependencies,
-        File sourceDirectory) throws InclusionScanException {
+        File sourceDirectory) throws InclusionScanException, IOException {
 
         // We don't want the plugin to run for every grammar, regardless of whether
         // it's changed since the last compilation. Check the mtime of the tokens vs
diff --git a/antlr4-maven-plugin/src/main/java/org/antlr/mojo/antlr4/GrammarDependencies.java b/antlr4-maven-plugin/src/main/java/org/antlr/mojo/antlr4/GrammarDependencies.java
index 6dee559ed..9f0fd1415 100644
--- a/antlr4-maven-plugin/src/main/java/org/antlr/mojo/antlr4/GrammarDependencies.java
+++ b/antlr4-maven-plugin/src/main/java/org/antlr/mojo/antlr4/GrammarDependencies.java
@@ -56,7 +56,7 @@ class GrammarDependencies {
      *
      * @return  self-reference.
      */
-    public String getPackage(List<String> arguments) {
+    private String getPackage(List<String> arguments) {
         int index = (arguments != null) ? arguments.indexOf("-package") : -1;
 
         return (index > -1)
@@ -90,7 +90,7 @@ class GrammarDependencies {
      * @return  self-reference.
      */
     public GrammarDependencies analyze(Set<File> grammarFiles,
-        Set<File> importGrammarFiles, Tool tool) {
+        Set<File> importGrammarFiles, Tool tool) throws IOException {
         log.debug("Analysing grammar dependencies " + sourceDirectory);
 
         // for dependency analysis we require all grammars
@@ -141,7 +141,7 @@ class GrammarDependencies {
      *
      * @return  {@code true} if a grammar used by the given grammar has been modified.
      */
-    public boolean isDependencyChanged(File grammarFile) {
+    public boolean isDependencyChanged(File grammarFile) throws IOException {
         String grammarPath = getRelativePath(grammarFile);
 
         for (Map.Entry<File, Map.Entry<byte[], Collection<String>>> e : grammars.entrySet()) {
diff --git a/antlr4-maven-plugin/src/main/java/org/antlr/mojo/antlr4/MojoUtils.java b/antlr4-maven-plugin/src/main/java/org/antlr/mojo/antlr4/MojoUtils.java
index 0a8cf03c3..b8019d88a 100644
--- a/antlr4-maven-plugin/src/main/java/org/antlr/mojo/antlr4/MojoUtils.java
+++ b/antlr4-maven-plugin/src/main/java/org/antlr/mojo/antlr4/MojoUtils.java
@@ -3,8 +3,10 @@ package org.antlr.mojo.antlr4;
 import java.io.File;
 import java.io.FileInputStream;
 import java.io.InputStream;
+import java.io.IOException;
 
 import java.security.MessageDigest;
+import java.security.NoSuchAlgorithmException;
 
 
 class MojoUtils {
@@ -15,7 +17,7 @@ class MojoUtils {
      *
      * @return  the checksum.
      */
-    public static byte[] checksum(File file) {
+    public static byte[] checksum(File file) throws IOException {
         try {
             InputStream in = new FileInputStream(file);
             byte[] buffer = new byte[2048];
@@ -36,8 +38,8 @@ class MojoUtils {
             }
 
             return complete.digest();
-        } catch (Exception ex) {
-            throw new RuntimeException("Could not create checksum " + file, ex);
+        } catch (NoSuchAlgorithmException ex) {
+            throw new IOException("Could not create checksum " + file, ex);
         }
     }